Bitcoin ATM is a good idea indeed. Though I never used one because there's no bitcoin ATM in our country. But I would love to try, hopefully if this was implemented in the future, the fees wont be that big or hopefull it is the same with fiat atm, no fees needed.
Well, there are fees when you withdraw cash on ATM's that are not their banks. Bitcoin ATM just like what you said is a really good idea since it will not let people who uses bitcoin an opportunity to withdraw, transfer, pay and even sell their bitcoins but it will make sort of advertisement. People will be curious on what bitcoin is because there is atm designated only for bitcoins.